title: The role of carbohydrate binding module (CBM) at high substrate consistency: comparison of Trichoderma reesei and Thermoascus aurantiacus Cel7A (CBHI) and Cel5A (EGII).
abstract: The role of CBM in two fungal model cellulase systems, consisting of Cel7A and Cel5A, from Trichoderma reesei and Thermoascus aurantiacus, were compared in the hydrolysis of various substrates. For comparison, family-1 CBM's were introduced to the T. aurantiacus and removed from the T. reesei enzymes. Especially at high dry matter consistencies of lignocellulosic substrates, pretreated wheat straw and spruce, the T. aurantiacus enzymes lacking CBM outperformed the enzymes carrying the CBM. In these conditions, the CBM-less enzymes from both organisms obviously recognized and bound to the substrate at higher probability than in dilute systems. Avoiding the unproductive binding to lignin caused by the CBMs obviously enhanced the hydrolytic performance. The lignin binding effect was, however, not entirely caused by the CBM, but also by the different structures and affinities of the core enzymes to lignin. Due to decreased binding, the CBM-less enzymes would allow reuse, potentially decreasing hydrolysis costs.
authors.affiliation: University of Helsinki, Food and Environmental Sciences, P.O. Box 27, 00014 Helsinki, Finland. tinaig.le.costaouec@gmail.com
authors.forename: Tinaïg
authors.initials: T
authors.lastname: Le Costaouëc
authors.forename: Annukka
authors.initials: A
authors.lastname: Pakarinen
authors.forename: Anikó
authors.initials: A
authors.lastname: Várnai
authors.forename: Terhi
authors.initials: T
authors.lastname: Puranen
authors.forename: Liisa
authors.initials: L
authors.lastname: Viikari
mesh_terms: D000327:Adsorption; D001426:Bacterial Proteins / Q000378:metabolism*; D050260:Carbohydrate Metabolism; D006868:Hydrolysis; D013379:Substrate Specificity; D055327:Thermoascus / Q000378:metabolism*; D014242:Trichoderma / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins
keywords: CBH; CBM; Cellulases; Cellulose binding module; DM; EG; Enzymatic hydrolysis; GH; HPAEC-PAD; High consistency; Lignocellulose; PEG; PS; PWS; carbohydrate binding module; cellobiohydrolase; dry matter; endoglucanase; glycoside hydrolase; high performance anion exchange chromatography with pulsed amperometric detection; polyethylene glycol; pretreated washed spruce; pretreated washed wheat straw